Proposal of Method Monitoring Macrocell Corrosion Rate at Existing Reinforced Concrete
Yoichi HIRAISHICShinichi MIYAZATOCNorihiko UMINO and Kazuo FUJIMOTO
Abstract:Recently, the investigation of the corrosion rate at the existing reinforced concrete was temporally evaluated only by the microcell corrosion rate using the polarization resistance method. That is, to appropriately evaluate the durability of the existing reinforced concrete, it is necessary to construct the check system that continuously measures not only the microcell corrosion rate but also the macrocell corrosion rate. From the above backgrounds, the objective of this study is to propose the method monitoring the macrocell corrosion rate at the existing reinforced concrete. Therefore, the technique for monitoring the macrocell corrosion rate by the non-destructive test is proposed using the specimen. Also, it is applied to the pier with a crack and the road bridge with a joint. As a result, the macrocell corrosion rate at the existing reinforced concrete can be continuously measured in all seasons. In this method, the Cupper boards etc. are set on the existing reinforced concrete, and the polarization resistance, the concrete resistance and the potential are measured in the arbitrary time. These measured values are substituted for the simulated electric circuit model of the macrocell in the reinforced concrete, and the macrocell corrosion rate is calculated. Especially, this method has the merit that can be used continuously for more than a year under the chloride environment. Key Words:Existing reinforced concrete, Non-destructive tests, Monitoring, Macrocell corrosion rate